XPost: aus.computers   
   From: nospam@needed.invalid   
      
   On Sun, 8/10/2025 8:23 PM, Felix wrote:   
   >   
   > I upgraded a linux box from LM 22 to LM 22.1 via software manager when   
   prompted, but now have no sound, because HDMI does not appear in sound manager   
   as an output option, only SPDIF. I have tried changing drivers. How to fix   
   please?   
   >   
   >   
      
      [Picture]   
      
       https://i.postimg.cc/3xbJ7gyz/LM221-soundworks-HDMI.png   
      
   The sound driver on three audio devices in INXI, is "snd_hda_intel",   
   because some controller in there, looks like a bus host for   
   HDAudio serial bus.   
      
   Video cards first had no sound. HDMI existed and worked, but   
   no 8ch LPCM (linear pulse code modulation) was available. The HDMI standard   
   defined how the audio samples were to be multiplexed in, but the cards   
   didn't have the logic block for it at the time.   
      
   The first HDMI "experiment", was to place a 2-channel SPDIF TTL-level signal on   
   a connector on the top edge of the video card. This should not require a   
   driver,   
   as the SPDIF was just multiplexed into HDMI right from the connector   
   (with suitable rate adaptation). A number of motherboards, had an SPDIF   
   connector   
   coming from the motherboard audio chip, but not a lot of users had the balls to   
   connect that signal to their (expensive) video card and risk blowing it. And   
   there   
   was no documentation (as usual), defining the electrical characteristic on   
   either end. It's just my *guess*, it was a TTL or 3.3V CMOS type logic signal,   
   with not a lot of drive capability (less than 8mA drive).   
      
   But this isn't particular "standards based". NVidia had the dinky connector.   
   AMD did not.   
   Was a patent involved ? Dunno.   
      
   The next thing that happened, is an HDAudio block was placed inside the   
   GPU. On AMD cards, they didn't want to write their own driver, so they   
   bought a driver (maybe a RealTek, I forget the branding of the driver).   
   Maybe AMD actually bought an HDAudio IP block (a logic block designed   
   by someone else), because AMD no longer enjoys crafting such shit.   
   The AMD southbridge today, is designed by Asmedia, as an example of how   
   much they enjoy designing USB host blocks. This all started when the   
   SB400 had a slower-than-normal USB2 block on it, AMD was ashamed, and   
   AMD then developed a phobia about doing any more of those. Whereas   
   NVidia fouled up regularly, made hardware mistakes, held head high   
   and made their next mistake and so on. You can't let these little things   
   bother you, in the hardware business. In the rush to market, everyone   
   is forced to make mistakes.   
      
   Eventually, both NVidia and AMD wrote their own branded HDAudio drivers, and   
   we are   
   then "at the level of operation standard today". On the Linux side, it   
   still needs a driver (of course), so some branding of a standard driver   
   must be present. Most of these "bodge" drivers, all they ever implemented   
   was stereo, which for a lot of people, is sufficient audio to keep beeps   
   and alerts and so on. You may find today, the 8ch LPCM, more "modes" are   
   available, but by default it is likely to be a stereo button. That   
   could be what you see in my picture.   
      
   Your job, is to dump an inxi -F   
   and see if the Audio section shares a common characteristic with mine.   
      
   Now, you didn't say what your video card is, but if your HDMI audio   
   worked before the upgrade, it should really work after the upgrade.   
   Even if Nouveau was driving the card, I think PNP can sniff the existence   
   of that logic block. It's not like the video driver status "blocks"   
   the audio. Obviously, if the crossbar is not working in the video card,   
   and there IS no HDMI signal at all, then a "working" HDAudio block in the   
   video card can do nothing for you. The HDMI signal has to be working,   
   as a minimal condition, and your machine should have a picture on the   
   HDMI monitor.   
      
       Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)